Capacitor and terminal stud assembly therefor



/9 I .9b M /j/ P 27205 i z E; E 1

I r 51 I III III];

| u 20 H I /6 INVEN TOR.

i/WZVG July 12, 1966 A. w. RlGAZlO 3,260,905

CAPACITOR AND TERMINAL STUD ASSEMBLY THEREFOR Filed Aug. 28, 1961 ATTORNEYS United States Patent 3,260,905 CAPACITOR AND TERMINAL STUDASSEMBLY THEREFOR Anthony Wayne Rigazio, Oglesby, Ill., assignor toElectrical Utilities Company, La Salle, 111., a corporation of IllinoisFiled Aug. 28, 1961, Ser. No. 134,316 Claims. (Cl. 317260) The presentinvention relates generally to a capacitor and method of manufacturingthe same. The present invention further relates to different types ofterminal assemblies including methods of manufacturing the same.

In accordance with the present invention, each of the terminalassemblies has a spring secured interally in assembly with it regardlessof whether the terminal assembly comprises a terminal stud type assemblyor a lead wire type of terminal assembly. By securing the springdirectly to the terminal assembly, it has been found that the cost ofmanufacture of the terminal assembly and of the capacitor may be reducedsince several parts which were formerly needed can now be eliminated bymanufacturing the terminal assembly and the capacitor in accordance withthis invention. It will further be appreciated that by reducing thenumber of parts that the component parts of the capacitor may beassembled with greater ease and at a labor reduced cost. Still further,it will be appreciated that by reducing the num ber of parts in thecapacitor that the manufacturing cost may be reduced.

According to an important feature of the present invention, the case orshell of the capacitor contains two narrow extrusions which protrudeinto the cup defined by the shell and which extend parallel to eachother to provide a low resistance type contact to the capacitor winding.

Another important feature concerns the fact that the capacitor isprovided with a spring that is formed from fiat spring material in sucha way as to exert high contact pressure between all contact surfaceswhen the components of the capacitor are assembled. The spring has abase as well as converging legs whereby it provides for a very lowcontact resistance between the legs of th spring and the other windingelectrode.

An important object of the present invention is to provide a new andimproved capacitor adapted for use principally in ignition and magnetoapplications for mechanical contact type associations therewith.

Another important object of the present invention is to provide a newand improved terminal assembly and method of manufacturing the same.

A further object of this invention is to provide a new and improved leadwire terminal assembly and method of manufacturing the same.

Yet another object of this invention is to provide a new and improvedterminal stud assembly and method of manufacturing the same.

Another and still further object of this invention is to provide a newand improved capacitor and method of manufacturing the same.

A further object of this invention is to provide a new and improvedcapacitor which provides a very low electrical contact resistance undersevere vibratory conditions whereby it will have long expected life andlend prongs or legs 20b-20b.

ice

itself to economical automated assembly at a minimum of expense.

Other objects and features of the present invention will more fullybecome apparent in view of the following detailed description taken inconjunction with the accompanying drawings and in which:

FIGURE 1 is a bottom view of a capacitor;

FIGURE 2 is an enlarged cross sectional view taken substantially on theline II-II looking in the direction indicated by the arrows, as seen inFIGURE 1;

FIGURE 3 is an enlarged exploded view of the components of the capacitorshown in FIGURES 1 and 2;

FIGURE 4 is a fragmentary partially cross sectioned side view of a leadwire type terminal assembly; and

FIGURE 5 is a side view of another modified type of terminal assembly.

As shown on the drawings:

The reference numeral 10 lesignates a capacitor which the shell 11 is acylindrical paper tube 16 which has its lower edge 16a engaged againstthe shell bottom- 12 and its upper edge 16b spaced below the beaded end15 of the shell 11. Mounted within the shell 11 is a conventional typeof foil winding 17.

After the paper tube 16 and the winding 17 have been mounted in theshell 11 a terminal assembly 18 is adapted to be telescoped within theopen end of the shell 11. A force is then exerted between the terminalassembly and the casing bottom 12 as the upper end of the cylindricalside wall 14 is shaped to provide the bead 15 whereby the components ofthe capacitor 10 are held in unitary assembly.

The drawings illustrate three different types of terminal assemblies asindicate at 18, and as further shown in FIGURES 4 and 5, all of whichare capable of assembly with the other components parts of thecapacitor, in the nut to be attached thereto in a conventional manner.

The stud sections 23 and 24 are provided with axial shoulders 25 and 26with the washer being adapted to engage against the shoulder 25 and withthe spring 20 being adapted to bottom against the stud shoulder 26. v

The spring 20 includes a base 20a as well as converging The base leg 20ahas a entral opening and the stud section 22 is engaged therein andprovided with a riveted end 27 securing the washer 19 as well as thespring 20 in unitary assembly with the stud 21.

When the components of the capacitor are assembled, the spring iscompressed so that the extrusions or ribs 13 are embedded in the bottomof the winding and so that the prongs 20b are embedded in the oppositeend of the winding. By engaging the winding between the ribs 13 and theprongs 20b the capacitor is adapted for very low electrical contactresistance under severe vibratory conditions. It will be appreciatedthat the head 15 when engaged against the washer 19 maintains the prongs205 as well as the ribs 13 in embedded engagement with respect to thewinding.

In FIGURE 4 is shown a modified type of terminal assembly indicatedgenerally at 38. The terminal assembly 38 includes an insulated wire 39having an outer layer of insulation 40 as well as a central wire 41. Asolderless connector 42 is secured to the wire 41 at one end in aconventional manner. A layer of additional insulation or tape 43 isprovided for covering the end of the wire 41.

A washer 45 is mounted on an opposite end of the insulated wire 39. Thewasher 45 is of the laminated type in that it is comprised of a layer ofrubber 46 and a layer of Bakelite 47. The washer 45 has a centraltubular passage indicated at 46a and 47a with a notched end 44 of theinsulated wire 39 secured in locked assembly therewith. The wire 41 hasits end turned radially with respect to its axis as indicated at 42which end is soldered at 43' to a clip 48. The turned end 42' extendsthrough a central passageway 48a. in the base leg of the clip 48. Theclip 48 is of the same configuration as the clip 20 described inconnection with the embodiment shown in FIGURES 1-3.

The terminal assembly 38 may be substituted for the terminal assembly 18and assembled with the shell 11 in the same manner previously described.

Shown in FIGURE is still another type of terminal assembly indicatedgenerally at 58. The terminal assembly includes a washer 19 and a clip20 which are secured to a stud 58' in the same way that the stud 18 issecured to its washer 19 and clip 20. The terminal assembly shown inFIGURE 5 differs from that shown in FIGURE 1 in that it is provided witha ditferent type of means including a transverse passageway 58a and aradially open ing groove area 58b for attachment with a connecting wire.The terminal assembly 58 may be assembled with a shell 11 in the sameway that the terminal assembly 18 is assembled with the shell.

In conclusion, it will be appreciated the capacitor herein disclosedacts as one terminal which is connected to the electrically groundedside of a circuit in which it is applied. One of the winding electrodesmakes electrical and mechanical contact with the bottom of the capacitorshell, the other winding electrode (or foil) makes electrical andmechanical contact with a flat spring which is formed from a strip ofmetal, as generally indicated at 20.

The spring 20 is compressed while it is in assembly with the othercomponent parts of the capacitor to provide a solid electrical contactand to maintain high mechanical pressure between all contact surfaces inthe capacitor and thus provides means to prevent arcing between saidcontact surfaces even under a severe mechanical vibrator condition. Thespring 20 is stacked to a terminal or soldered to a lead wire which isin turn electrically insulated from the capacitor case to complete theelectrical circuit.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention:

1. A method of manufacturing a capacitor which comprises forming acup-shaped shell, inserting a winding in said shell, forming a terminalstud assembly with a fiat spring on one end, inserting the terminal intoan open end of the cup-shaped shell and compressing the spring againstthe winding, and bending an upper edge of the shell whilecontemporaneously engaging the bead against an outside surface of theterminal stud assembly securing said spring 4 and said winding undercompression in said cup-shaped shell.

2. A method of manufacturing a capacitor which comprises forming acup-shaped she-ll defining a cup with extrusions on its bottomprotruding into the cup, inserting a winding in said shell and restingit on said extrusions, forming a terminal stud assembly with a prongedspring on one end, inserting the terminal stud assembly into an open endof the cup-shaped shell, and heading an upper edge of the shell whilecontemporaneously engaging the head against an outside surface of theterminal stud assembly securing said spring and said winding undercompression in said cup-shaped shell.

3. A method of manufacturing a capacitor which comprises forming acup-shaped shell defining a cup with extrusions on its bottom protrudinginto the cup, inserting a winding in said shell and resting it on saidextrusions, forming a terminal stud assembly with a spring having prongson one end, inserting the terminal stud assembly into an open end of thecup-shaped shell, and beading an upper edge of the shell with the beadbeing engaged against an outside surface of the terminal stud assemblysecuring said spring and said winding under compression in saidcup-shaped shell, the prongs and the extrusions being embedded inopposite ends of the winding and with a bottom end of the windingengaged flush against the bottom of the cup-shaped shell.

4. A method of manufacturing a lead wire assembly comprising the stepsof forming a length of insulated wire with the wire extending beyond'theinsulation at one end leaving a portion of the wire bare, stacking awasher on the bare wire with the insulation having an edge supportingthe washer at one end of the Wire, stacking a metal spring on the washerwith the bare wire extending through the washer and the spring, andbending the bare wire extending beyond the spring over into engagementwith a side of the spring thereby securing the washer and the spring inunitary assembly.

5. A method of manufacturing a lead wire assembly comprising the stepsof forming a length of insulated wire with the wire extending beyond theinsulation at one end leaving a portion of the wire bare, stacking awasher on the bare wire with the insulation having an edge supportingthe washer at one end of the wire, stacking a metal spring on the washerwith the bare wire extending through the washer and the spring, bendingthe bare wire extending beyond the spring over into engagement with aside of the spring, and attaching the bent portion of the wire with thespring thereby securing the washer and the spring in unitary assembly.

6. A method of manufacturing a lead wire assembly comprising the stepsof forming a length of insulated wire having a solderless connector atone end and with the wire extending beyond the insulation at an oppositeend leaving a portion of the wire bare, stacking a washer on the barewire with the insulation having an edge supporting the washer at one endof the wire, stacking a metal spring on the washer with the bare wireextending through the washer and the spring, and bending the bare wireextending beyond the spring over into engagement with a side of thespring thereby securing the washer and spring in unitary assembly.

7. A method of manufacturing a terminal stud assembly including thesteps of forming a terminal stud with an axially facing annular shoulderintermediate its opposite ends, stacking a washer and a spring on saidstud With said washer engaged against the shoulder, and riveting one ofits opposite ends securing the spring and the washer in unitary assemblywith the stud.

8. A terminal stud assembly for insertion as a unit into an open end ofa capacitor container including a terminal stud with an axially facingannular shoulder intermediate its opposite ends, a circular Washer and aspring stacked on one of said opposite ends with the Washer engagedagainst the shoulder and with the spring engagec against said washer,said spring being mounted coaxially of said circular washer and withsaid spring having a base of smaller dimension than a diameter of saidcircular washer, said one of said opposite ends being enlarged andmaintaining the spring and the washer in assembled relation with saidstud.

9. A terminal stud assembly for insertion as a unit into an open end ofa capacitor container including a terminal stud with an axially facingannular shoulder intermediate its opposite ends, an annular washer and aspring stacked on one'of said opposite ends with the washer engagedagainst the shoulder and with the spring engaged against said Washer,said one of said opposite ends being enlarged and maintaining the springand the washer in assembled relation with said stud, said spring havinga flat base and converging prongs secured at opposite ends of said base,said spring being mounted coaxially of said annular washer and with saidwasher having a greater width than the length of said-flat base.

10. A capacitor which comprises a cup-shaped shell defining a cup withextrusions on its bottom protruding into the cup, a winding in saidshell and resting on said extrusions, a terminal stud assembly with aspring on one end disposed in an open end of the cup-shaped shell, and abead on an upper edge of the shell engaged against an outside surface ofthe terminal stud assembly securing said spring and said winding undercompression in said cup-shaped shell, said spring comprising a flatmetal strip having converging prongs at opposite ends engaged againstsaid winding.

11. A capacitor which comprises a cup-shaped shell defining a cup, apaper tube in said cup, a winding disposed inside said paper tube insaid cup, and a lead wire assembly disposed in an open end of said cup,said lead wire assembly including an insulated wire, a washer and aspring secured to one end of said insulated wire and with an end of saidwire projecting through said washer and being locked in assemblytherewith, and connecting means joining said end with said spring, saidspring being engaged against said winding, said spring, washer and saidinsulated wire being removable from said cup and insertable into saidcup in unison together, said shell having a bead at its open end engagedagainst said washer securing said spring and said winding undercompression in said shell.

12. A capacitor which comprises a cup-shapedshell defining a cup, apaper tube in said cup, -a winding disposed inside said paper tube insaid cup, and a lead wire assembly disposed in an open end of said cup,said lead wire assembly including an insulated wire, a washer and aspring secured to one end of said insulated wire, said spring beingengaged against said winding, said spring, washer and said insulatedwire being removable from said cup and insertable into said cup inunison together, said shell having a bead at its open end engagedagainst said washer securing said spring and said winding undercompression in said shell, said spring having a base and convergingprongs embedded in said Winding.

13. The capacitor of claim 11 further characterized by said shell havingparallel rib-like extrusions on its bottom protruding into the cup andwith said extrusions being embedded in the winding whereby the windingis engaged flush against the bottom of the shell.

14. A capacitor which comprises a cup-shaped shell defining the cup, apaper tube in said cup, a winding disposed inside of said paper tube insaid cup, a terminal assembly disposed in said cup, the terminalassembly including a washer engaged against an upper end of said papertube, the terminal assembly 'further including a pronged spring mountedon an underside of said washer and with saidpronged spring having itsprongs engaged against said winding, said terminal assembly includingsaid spring and said washer being removable from said cup and insertableinto said cup in unison together, and means engaged between said shelland said washer securing said spring and said winding under compressionin said cup-shaped shell.

15. The capacitor of claim 14 further characterized by said terminalassembly including a stud with said stud being riveted in assembly withsaid washer and said spring.

16. The capacitor of claim 14 further characterized by said terminalassembly comprising a lead wire assembly including an insulated wire,the insulated wire being secured in assembly with said washer and saidspring.

17. A capacitor which comprises a metallic cup-shaped shell defining acup and having a cylindrical Wall joined with a bottom at one end, anon-conductive tube in said cup, a winding disposed inside of saidtubeand engaged on the bottom of said cup, a terminal assembly mountedin assembly with said shell and including a terminal element, at flatnon-metallic washer having a diameter approximating an inside diameterof said cylindrical wall, a spring disposed on an underside of saidwasher and comprising a flat spring metal strip of greater length thanwidth and having a flat central portion with opposite ends underturnedand disposed in converging relation with respect to the flat centralportion and comprising converging prongs, means securing said flatnon-metallic washer and said fiat central portion of said spring inflush contact against one another and in fixed assembly with saidterminal element, and means comprising a bead on an axially outer end ofthe cylindrical wall engaged against said washer securing free ends ofsaid converging prongs under compression against said winding and forholding said winding against the bottom of the cup, the spring providinghigh contact pressure between all surfaces engaged therewith andproviding low contact resistance between the prongs and a windingelectrode engaged therewith, said bottom of .said cup having parallelribs embedded in said winding to provide a low resistance type contactwith the winding.

18. A capacitor which comprises a metallic cup-shaped shell defining acup and having a cylindrical wall joined with a bottom at one end, anon-conductive tube in said.

cup, a winding disposed inside of said tube and engaged on the bottom ofsaid cup, a terminal assembly mounted in assembly with said shell andincluding a terminal element, a flat non-metallic washer having adiameter approximating an inside diameter of said cylindrical wall, aspring disposed on an underside of said washer and comprising a flatspring metal strip of greater length than width and having a flatcentral portion with opposite ends underturned and disposed inconverging relation with respect to the fiat central portion andcomprising converging prongs, means securing said fiat non-metallicwasher and said flat central portion of said spring in flush contactagainst one another and in fixed assembly with said terminal element,and means comprising a bead on an axially outer end of the cylindricalwall engaged against said washer securing free ends of said convergingprongs under compression against said winding and for holding saidwin-ding against the bottom of the cup, the spring providing highcontact pressure between all surfaces engaged therewith and providinglow contact resistance between the prongs and a winding electrodeengaged therewith.

19. The capacitor of claim 18 further characterized by said terminalelement comprising a metallic stud.

20. The capacitor of claim 18 further characterized by said terminalelement comprising a lead wire having a solderless connector on its endremote from said washer.

References Cited by the Examiner UNITED STATES PATENTS 1,580,873 4/1926Weldon 3 l7260 1,636,328 7/1927 Sauer 3 l7260 2,029,430 2/1936 Kopin-Ski317270 (Other references on following page) UNITED 7 8 STATES PATENTS2,963,775 12/1960 Chadwick 29-15555 Edmundson 317 26O 3,109,127 10/1963Guetersloh 317-260 Schneider 317-260 FOREIGN PATENTS Ramos 339-253 MWagner 29 25-42 5 1,148,001 12/1957 Trance. LEWIS ROBERT K. SCHAEFER,Prinmry Examine/ Modrey 339-220 Clemons JOHN F. BURNS, Exammcr. Riley317-242 I. S. RAPPAPORT, E. GOLDBERG, Clark 29-15555 10 AssistantExaminers.

Clemons 29-25 .42

8. A TERMINAL STUD ASSEMBLY FOR INSERTION AS A UNIT INTO AN OPEN END OFA CAPACITOR CONTAINER INCLUDING A TERMINAL STUD WITH AN AXIALLY FACINGANNULAR SHOULDER INTERMEDIATE ITS OPPOSITE ENDS, A CIRCULAR WASHER AND ASPRING STACKED ON ONE OF SAID OPPOSITE ENDS WITH THE WASHER ENGAGEDAGAINST THE SHOULDER AND WITH THE SPRING ENGAGED AGINST SAID WASHER,SAID SPRING BEING MOUNTED COAXIALLY OF SAID CIRCULAR WASHER AND WITHSAID SPRING HAVING A BASE OF SMALLER DIMENSION THAN A DIAMETER OF SAIDCIRCULAR WASHER, SAID ONE OF SAID OPPOSITE ENDS BEING ENLARGED ANDMAINTAINING THE SPRING AND THE WASHER IN ASSEMBLED RELATION WITH SAIDSTUD.
 11. A CAPACITOR WHICH COMPRISES A CUP-SHAPED SHELL DEFINING A CUP,A PAPER TUBE IN SAID CUP, A WINDING DISPOSED INSIDE SAID PAPER TUBE INSAID CUP, AND A LEAD WIRE ASSEMBLY DISPOSED IN AN OPEN END OF SAID CUP,SAID LEAD WIRE ASSEMBLY INCLUDING AN INSULATED WIRE, A WASHER AND ASPRING SECURED TO ONE END OF SAID INSULATED WIRE AND WITH AN END OF SAIDWIRE PROJECTING THROUGH SAID WASHER AND BEING LOCKED IN ASSEMBLYTHEREWITH, AND CONNECTING MEANS JOINING SAID END WITH SAID SPRING, SAIDSPRING BEING ENGAGED AGAINST SAID WINDING, SAID SPRING, WASHER AND SAIDINSULATED WIRE BEING REMOVABLE FROM SAID CUP AND INSERTABLE INTO SAIDCUP IN UNISON TOGETHER, SAID SHELL HAVING A BEAD AT ITS OPEN END ENGAGEDAGAINST SAID WASHER SECURING SAID SPRING AND SAID WINDING UNDERCOMPRESSION IN SAID SHELL.